After about half hour of highway driving my truck has been heating up a lot . If I turn the heat up and roll down the window it does fine... This works for winter but it summer it's going to be worse. What are common causes for this? Just got a new water pump

 

Did you burp the system after the install of the new pump.
Could be the cause.

 

Bad thermostat?

 

Yeah im sure it has an air bubble in the system. Not sure on the Dodges but on my old Nissan there was two hoses on the firewall that ran into the heater core under the dash and you could take one loose with the radiator cap off and stick a running water hose over it and it would flush out the air.

 

If it started to do it after the water pump change, you have an air bubble. If it started to do it before the water pump change, you might have a partially clogged radiator.

 

It's after the water pump, especially towing a trailer I have to crank the heat to keep the temp down!

 

X2 on air bubble

 

Well, I went thru this last year. Started with thermostat. Then water pump. Then finally replaced radiator. Problem solved!

 

How do you guys measure the coolant level? I only have a fill and it's dark and hard to see how full it is

 

Is your antifreeze % the same or did you water it down just add water no antifreeze?